diff --git a/src/cmd/go/testdata/script/test_cleanup_failnow.txt b/src/cmd/go/testdata/script/test_cleanup_failnow.txt
index 5ad4185fc10..0737a93db21 100644
--- a/src/cmd/go/testdata/script/test_cleanup_failnow.txt
+++ b/src/cmd/go/testdata/script/test_cleanup_failnow.txt
@@ -1,11 +1,25 @@
 # For issue 41355
 [short] skip
 
+# This test could fail if the testing package does not wait until
+# a panicking test does the panic. Turn off multithreading, GC, and
+# async preemption to increase the probability of such a failure.
+env GOMAXPROCS=1
+env GOGC=off
+env GODEBUG=asyncpreempt=off
+
+# If the test exits with 'no tests to run', it means the testing package
+# implementation is incorrect and does not wait until a test panic.
+# If the test exits with '(?s)panic: die.*panic: die', it means
+# the testing package did an extra panic for a panicking test.
+
 ! go test -v cleanup_failnow/panic_nocleanup_test.go
+! stdout 'no tests to run'
 stdout '(?s)panic: die \[recovered\].*panic: die'
 ! stdout '(?s)panic: die \[recovered\].*panic: die.*panic: die'
 
 ! go test -v cleanup_failnow/panic_withcleanup_test.go
+! stdout 'no tests to run'
 stdout '(?s)panic: die \[recovered\].*panic: die'
 ! stdout '(?s)panic: die \[recovered\].*panic: die.*panic: die'
 
diff --git a/src/testing/testing.go b/src/testing/testing.go
index d86354093a4..a44c0a07497 100644
--- a/src/testing/testing.go
+++ b/src/testing/testing.go
@@ -1091,10 +1091,16 @@ func tRunner(t *T, fn func(t *T)) {
 		// complete even if a cleanup function calls t.FailNow. See issue 41355.
 		didPanic := false
 		defer func() {
-			t.signal <- signal
-			if err != nil && !didPanic {
+			if didPanic {
+				return
+			}
+			if err != nil {
 				panic(err)
 			}
+			// Only report that the test is complete if it doesn't panic,
+			// as otherwise the test binary can exit before the panic is
+			// reported to the user. See issue 41479.
+			t.signal <- signal
 		}()
 
 		doPanic := func(err interface{}) {